Attic Air Sealing Before Insulation: The Energy-Efficiency Step People Miss

Adding attic insulation can improve home energy efficiency—but air sealing should come first when appropriate leakage pathways are present. In this BPMS™ building-performance Short, learn why attic insulation and attic air sealing perform different jobs, where common attic air leaks can hide, how blower-door testing can strengthen an energy audit, and why simply covering leakage pathways with additional insulation may leave an important building-envelope problem unresolved. ENERGY STAR identifies common attic leakage locations including attic hatches, plumbing and wiring penetrations, dropped soffits, kneewalls, recessed-light areas and mechanical chases. EPA also recommends completing attic air sealing before adding attic insulation. You’ll learn: • Why insulation is not automatically an air barrier • Common locations for hidden attic bypasses • How blower-door testing supports diagnostic work • Why air sealing should precede additional attic insulation • How air sealing and insulation can improve comfort and efficiency together • Why moisture, combustion venting, electrical conditions and suspect materials require appropriate safety evaluation ENERGY STAR estimates that homeowners can save an average of approximately 15% on heating and cooling costs by air sealing and adding insulation in attics, floors over crawlspaces and basements, although actual savings depend on the home and work performed. For energy auditors, weatherization contractors, insulation professionals, HVAC contractors, HERS raters and building-science professionals, the principle is straightforward: Measure → Diagnose → Improve → Verify Learn more about BPMS™ at BPMSCloud.com⁠. #Shorts #AirSealing #AtticInsulation #EnergyAudit #Weatherization #BuildingScience Current authoritative references https://www.energystar.gov/saveathome/seal_insulate/do-it-yourself-guide/sealing-air-leaks-attic?utm_source=chatgpt.com ENERGY STAR — Attic Insulation Project⁠ ENERGY STAR — Why Seal and Insulate?⁠

Originally uploaded October 14, 2026